Where we needed to change tactics was with some Dell Latitude 2100 machines. Our set of install DVDs wouldn't work because they are 32 bit and don't have optical drives. We consider netboot install, but that seemed overly complicated. So a USB-based solution... the easy answer is to just install Xubuntu from USB Stick, but since the devices are mostly identical perhaps an imaging solution.
There are two options here. One option is similar to netboot, but we chose instead to create a few USB drives that would boot the computer and automatically clone a previously-created image on to the hard drive.
So now all a student (or teacher) needs to do in order to set up a new machine (or "fix" a machine that a student has "adjusted") is to insert the USB drive, turn on the computer, press F12, and boot from the USB Storage Device.